TRANSLOCATION OF RECOMBINANT P47(PHOX) CYTOSOLIC COMPONENT OF THE PHAGOCYTE OXIDASE BY IN-VITRO PHOSPHORYLATION

Activation of superoxide-generating NADPH oxidase system of human neut rophils involves phosphorylation-dependent translocation of p47(phox) and other cytosolic components to the plasma membrane. In contrast to the stimulation of the NADPH oxidase in intact cells, however, the act ivation of cell-free system requires the addition of anionic amphiphil es such as sodium dodecyl sulfate (SDS) and arachidonate. In this syst em, translocation of p47(phox) is also an essential step for activatio n, but phosphorylation is not required. The basis of this difference i n oxidase activation is not yet clear. We now report that in a cell-fr ee oxidase system, phosphorylated recombinant p47(phox) can be translo cated to the membrane in the absence of SDS or arachidonate. These fin dings suggest that both phosphorylation and SDS could cause a common c hange in conformation or charge of p47(phox) that may result in the as sociation of p47(phox) with the plasma membrane. (C) 1995 Academic Pre ss, Inc.